Question: Khan.scratchpad.disable(); For every level Stephanie completes in her favorite game, she earns $420$ points. Stephanie already has $400$ points in the game and wants to end up with at least $2790$ points before she goes to bed. What is the minimum number of complete levels that Stephanie needs to complete to reach her goal?
Solution: To solve this, let's set up an expression to show how many points Stephanie will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Stephanie wants to have at least $2790$ points before going to bed, we can set up an inequality. Number of points $\geq 2790$ Levels completed $\times$ Points per level $+$ Starting points $\geq 2790$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 420 + 400 \geq 2790$ $ x \cdot 420 \geq 2790 - 400 $ $ x \cdot 420 \geq 2390 $ $x \geq \dfrac{2390}{420} \approx 5.69$ Since Stephanie won't get points unless she completes the entire level, we round $5.69$ up to $6$ Stephanie must complete at least 6 levels.